Abstract:

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HfC powders were synthesized by carbothermal reduction of modified hafnium alkoxide precursors using hafnium oxychloride, propanol and 2,4-pentanedione as the starting materials. The structure, composition and reaction mechanism of the solution-derived precursor were studied by FT-IR. The forming process of HfC was detected by TG-DSC-FT-IR and XRD, and the formation mechanism was also discussed. The morphology of as-derived HfC powders was observed by SEM. The research showed that the solution-derived precursors of HfC probably had structures of network or chain. Dried precursors showed a honeycomb structure. When pyrolysed, the precursors was firstly converted to HfO2 and amorphous C. HfO2 was deoxidized gradually above 1500 . It seemed that HfC powders were almost pure after heat treatment at 1800 .